Twin directories of books:

[DIR]  ftp://ftp.ox.ac.uk/pub/crypto/pgp/pgpi/5.5/books/
[DIR]  ftp://ftp.mimuw.edu.pl/mirror/ftp.inria.fr/INRIA/Projects/cristal/caml-light/books/
[DIR]  ftp://ftp.kemsu.ru/pub/mirrors/www.linux.org.ru/books/
[DIR]  ftp://ftp.dit.upm.es/pub/doc/books/
[DIR]  ftp://ftp.dit.upm.es/mirrors/ftp.ifi.uio.no/pub/pgp/5.5/books/
[DIR]  ftp://ftp.dit.upm.es/mirrors/ftp.ox.ac.uk/pub/crypto/pgp/pgpi/5.5/books/
[DIR]  ftp://ftp.ifam.uni-hannover.de/pub/books/
[DIR]  ftp://ftp.reed.edu/mirrors/faqs/crafts/textiles/books/
[DIR]  ftp://ftp.reed.edu/mirrors/faqs/misc-kids/books/
[DIR]  ftp://ftp.reed.edu/mirrors/faqs/sports/skating/books/
[DIR]  ftp://ftp.reed.edu/mirrors/faqs/books/
[DIR]  ftp://ftp.eenet.ee/pub/cpan/doc/misc/books/
[DIR]  ftp://ftp.eenet.ee/arhiiv/mysql/images/portal/books/
[DIR]  ftp://ftp.eenet.ee/arhiiv/mysql/portal/books/
[DIR]  ftp://ftp.eenet.ee/arhiiv/pgp/5.5/books/
[DIR]  ftp://ftp.arnes.si/books/
[DIR]  ftp://ftp.eutelia.it/pub2/CPAN_Mirror/doc/misc/books/
[DIR]  ftp://ftp.fi.upm.es/pub/kde/img/books/
[DIR]  ftp://ftp.saintjoe.edu/pub/CPAN/doc/misc/books/
[DIR]  ftp://ftp.uni-frankfurt.de/pub/Mirrors/ftp.kde.org/pub/kde/doc/books/
[DIR]  ftp://ftp.inf.utfsm.cl/pub/crypto/pgp/pgpi/5.5/books/
[DIR]  ftp://ftp.sdsmt.edu/pub/choralnet/reference/books/
[DIR]  ftp://ftp.psg.com/pub/modula-2/gpm/books/
[DIR]  ftp://ftp.psg.com/pub/modula-2/gpm/readingroom/books/
[DIR]  ftp://ftp.hpl.hp.com/gatekeeper/pub/published/books/
[DIR]  ftp://ftp.vernet.lv/pub/misc/books/
[DIR]  ftp://ftp.afps.chel.su/pub/UNIX/books/
[DIR]  ftp://ftp.kfki.hu/pub/packages/security/pgp/pgpi/5.5/books/
[DIR]  ftp://ftp.kfki.hu/pub/packages/perl/CPAN/doc/misc/books/
[DIR]  ftp://mirddin.farlep.net/pub/books/
[DIR]  ftp://ftp.qrz.ru/pub/hamradio/books/
[DIR]  ftp://62.128.1.71/pub/CPAN/doc/misc/books/
[DIR]  ftp://ftp.rdc.cl/pub/Unix/Linux/Perl/CPAN/doc/misc/books/
[DIR]  ftp://ftp.skynet.be/mirror1/tucows.skynet.be/pda/wince/books/
[DIR]  ftp://ftp.skynet.be/mirror1/tucows.skynet.be/pda/epoc/files/books/
[DIR]  ftp://128.232.0.33/pub/crypto/pgp/pgpi/5.5/books/
[DIR]  ftp://FusedImage00013871.jpg/pub/crypto/pgp/pgpi/5.5/books/
[DIR]  ftp://ftp.etext.org/pub/Politics/World.Systems/books/
[DIR]  ftp://ftp.etext.org/pub/Politics/MIM/bpp/books/
[DIR]  ftp://ftp.etext.org/pub/Politics/MIM/bookstore/books/
[DIR]  ftp://ftp.kreonet.re.kr/tools/db/mysql/books/
[DIR]  ftp://ftp.kreonet.re.kr/tools/X11/kde/doc/books/
[DIR]  ftp://ftp.kreonet.re.kr/languages/CPAN/doc/misc/books/
[DIR]  ftp://ftp.cs.toronto.edu/pub/usenet/news.answers/books/
[DIR]  ftp://ftp.cs.toronto.edu/doc/books/
[DIR]  ftp://ftp.lehigh.edu/pub/listproc/qrp-l/books/
[DIR]  ftp://ftp.fvwm.org/pub/Amiga/comp.sys.amiga.reviews/other-reviews/books/
[DIR]  ftp://ftp.inf.uos.de/pub/axel/books/
[DIR]  ftp://ftp.inf.uos.de/pub/hanser/books/
[DIR]  ftp://ftp.cs.uregina.ca/pub/class/115/pre-071/sun_tutor/books/